The invention relates to a device for contact-free guidance of a web-like material over a surface, such as a folder former plate, for example, the web-like material being foldable with a first longitudinal fold which is formed therein as it passes the folder former plate.
The published German Patent Document DE 199 15 386 A1 is concerned with a device for avoiding smearing during the transportation of a printed material web, which may be printed on one or both sides thereof. This publication describes a device by which the smearing of ink on a printed web is avoided by increasing the viscosity of the ink printed onto the web. The increase in viscosity takes place following a first operation for cooling the web. The cooling device that is used may include rollers which are arranged within a rotary printing machine and are cooled by a coolant. On the other hand, the cooling may be effected by air cooling a closed section of the rotary printing machine or by feeding a cooling gas onto the surface of the printed material web.
U.S. Pat. No. 5,799,616 discloses a folder former nose which may be fastened on the folder former of a rotary printing machine. The folder former nose includes a base plate wherein a triangular plate is positioned. A cover plate is displaceably disposed on the triangular plate. Provided in the cover plate are openings which are formed by cutouts in the border region of the cover plate. A fluid flow, which prevents the web material running off on the folder former nose from coming into contact with the surface of the folder former nose, to pass out through the openings, in the border region of the folder former nose. By actuating motors connected to the displaceable cover plate, or of pneumatically actuating devices, it is possible to adjust the size of the opening of the cutouts on the folder former nose, as a result of which the outgoing fluid volume flow can be adapted to the rate of travel of the web-like materials conveyed over the former nose.
U.S. Pat. No. 5,947,411 and the published European Patent Document EP 0 945 385 A2 disclose a first longitudinal folding device for use in a web-fed rotary printing machine, wherein it is possible to regulate the fluid volume flow acting upon the surfaces of the folder former plate. For this purpose, the folder former plate is configured with two bases. Fluid volume flow outlets which are located above one another, and are distributed over the length of the folder former plate, are arranged in the base plate located beneath the folder former plate, whereon the web-like material runs off. Wedge-shaped adjusting elements are accommodated in the cavity between the folder former plate and the plate wherein the air-outlet openings are formed, the adjusting elements either increasing or reducing the size of the outlet openings for the fluid volume flow onto the upper side of the folder former plate. It is thus possible to adjust, on the upper side of the folder former plate, the volume flow passing through the correspondingly adjusted opening cross sections. The openings, which are bounded via the wedge-shaped displaceable adjusting elements, are formed, in the transition region of the folder former plates, in circular former bars, over the circumferential surface of which there exits the fluid volume flow passing out of the openings, contact of the web-like material both with the folder former bars and with the folder former plate thus being avoided. The regulation of the emerging or outgoing fluid volume flow which can be achieved by this construction involves an extremely high level of outlay, and requires a longitudinal folding configuration formed with two bases. Furthermore, the positioning accuracy of the wedge-shaped elements, which release or bound the outlet openings for the emerging volume flow, requires a high level of accuracy, which results in the associated actuating drives being correspondingly more costly.
The published Japanese Patent Document JP-H-7-47415 discloses a triangular folder former plate on a folder of a rotary printing machine. The surface of the folder former is provided with a multiplicity of openings. Positioned in these openings are spherical elements which are enclosed by corresponding holders or sockets. The spherical elements of the folder former plate are subjected to the action of individual spring elements positioned in the holders. A volume flow of a fluid is introduced into each of the holders, because each of the holders is provided with a compressed-air connection. Depending upon the movement of the spherical element accommodated in the respective holder, a volume flow onto the surface of the folder former plate is released or blocked.
Starting from the state of the art exemplified hereinbefore, wherein sometimes very complex proposals have been made for regulating the emerging or outgoing fluid volume flow for guiding, as contact-free as possible, a material web running off over a folder former plate, it is an object of the invention to provide a device for contact-free guidance of web-like material over a surface whereby contact-free run-off of the web-like material having different widths is regulated, with compressed-air losses which are as low as possible and with relatively simple equipment being employed in a first longitudinal folding arrangement.
With the foregoing and other objects in view, there is provided, in accordance with a first aspect of the invention, a device for contact-free guidance of a web material over a surface element whereon a first longitudinal fold is formed in the web material, comprising respective crossmembers disposed at the top and at the bottom of the surface elements, the surface element decreasing in width continuously from the top crossmember to the bottom crossmember, and being defined by boundary elements, the surface element and the boundary elements having a gaseous medium provided therein, an adjustable closure element for varying, in accordance with a respective format of the web material guided over the surface, a flow of a volume of the gaseous medium from an air cushion formed beneath the web material.
In accordance with another feature of the invention, the surface member has a surface disposed in a travel direction of the web material, the surface being formed with a plurality of openings disposed behind one another in the travel direction of the web material.
In accordance with a further feature of the invention, the openings, respectively, have a longitudinal extent exceeding, by a multiple, a transverse extent thereof in the surface.
In accordance with an added feature of the invention, at a rear side of the surface, the closure element faces towards at least one of the openings formed in the surface, the closure element being engageable with and being disengageable from the rear side of the surface.
In accordance with an additional feature of the invention, the closure element has a width exceeding the width of the openings formed in the surface.
In accordance with yet another feature of the invention, the closure element is mounted at a top end thereof so as to be pivotable about a pin.
In accordance with yet a further feature of the invention, the closure element extends, in the travel direction of the web material, between the top and the bottom crossmembers of a longitudinal folding device.
In accordance with yet an added feature of the invention, the closure element is manually adjustable from a position wherein it has been engaged with the surface, into a position wherein it is disengaged from the surface, and the reverse.
In accordance with yet an additional feature of the invention, the closure element is adjustable via an actuating drive acting upon spindle elements, from a position wherein it has been engaged with the surface, into a position wherein it is disengaged from the surface, and the reverse.
In accordance with still another feature of the invention, a threaded section formed on one of the spindle elements extends through an actuating lever for a cam, and has stops thereon for limiting vertical movement of the actuating lever.
In accordance with still a further feature of the invention, the closure element is pivotably mounted on the top crossmember.
In accordance with still an added feature of the invention, the surface element is a former plate, and the closure element is engageable more firmly with the first opening in the surface, as viewed in the web-travel direction, than with the adjacent openings in the former plate, as viewed in the web travel direction.
In accordance with still another feature of the invention, the closure element is pivotably mounted on the top crossmember and, on the bottom crossmember, is mounted on an adjustable pivoting cam supported by a carrier.
In accordance with another feature of the invention, the actuating lever for the cam serves for executing a vertical movement, as viewed in the web travel direction, for causing the cam, which is pivotable about an actuating pin, to execute a retraction and an extension movement, respectively.
In accordance with a second aspect of the invention, there is provided a device for forming a first longitudinal fold on one of a material web and material-web lengths, respectively, printed on at least one side thereof, which are guided in a contact-free manner over a surface element continuously decreasing in width from a top crossmember to a bottom crossmember, and being defined by boundary elements, the surface element and the boundary elements being formed with openings for a gaseous medium, comprising an adjustable closure element for varying, in accordance with a respective format of the web material guided over the surface, a flow of a volume of gaseous medium from an air cushion formed beneath the web material.
In accordance with a third aspect of the invention, there is provided an angle-bar superstructure having a device for forming a first longitudinal fold on one of a material web and material-web lengths, respectively, printed on at least one side thereof, which are guided in a contact-free manner over a surface element continuously decreasing in width from a top crossmember to a bottom crossmember, and being defined by boundary elements, the surface element and the boundary elements having openings for gaseous medium provided therein, comprising an adjustable closure element for varying, in accordance with a respective format of the web material guided over the surface, a flow of a volume of the gaseous medium from an air cushion formed beneath the web material.
In accordance with a fourth aspect of the invention, there is provided a web-processing rotary printing machine having a device for forming a first longitudinal fold on one of a material web and material-web lengths, respectively, printed on at least one side thereof, which are guided in a contact-free manner over a surface element continuously decreasing in width from a top crossmember to a bottom crossmember, and being defined by boundary elements, the surface element and the boundary elements having openings for gaseous medium provided therein, comprising an adjustable closure element for varying, in accordance with a respective format of the web material guided over the surface, a flow of a volume of the gaseous medium from an air cushion formed beneath the web material.
The advantages of the proposed device according to the invention are, in particular, that the air cushion produced, via the air outlet, from the air volume emerging from the surface-bounding elements can be varied on the outflow side simply via a very slight adjusting movement of a sheet-like element. This makes it possible for the air cushion emerging beneath the material web, which is to be guided, to be easily influenced without having any effect upon the compressed-air source. Depending upon the extent to which the closure element located on the rear side of the surface or surface element, for example, of a first longitudinal folding device has been adjusted, an air cushion which covers the width of the guide surface, i.e., of the former plate, is formed in the case of a maximum web width, the air cushion being fed by the air volume flows emerging from the former bars. Beneath the openings which are formed in the former plate and located behind one another, as viewed in the web travel or web-running direction, the closure element, which may be pivotable about a pin, acts as a throttling or restrictor element which throttles or restricts the flows of volumes of air flowing out of the air cushion, depending upon the extent to which it has been engaged with the rear side of the guide surface.
In a further advantageous configuration of the device proposed in accordance with the invention, a number of openings located behind one another, as viewed seen in the travel direction of the web-like material, are formed in the surface, for example, the top side of a former plate. The longitudinal extent of these openings exceeds by a multiple the transverse extent thereof in the surface above which the air cushion is formed beneath the web material. This configuration ensures that, by a just slightly adjustable closure element extending in the web travel direction, it is possible for the air cushion beneath the material web which is to be conveyed to be influenced in the longitudinal extent of the material web so that both materials of large width extents, i.e. large formats, and materials of small formats can be processed, and it is possible, in particular, for the formation of the air cushion beneath the material web, above the former plate, to be adapted to the width of the printing material, respectively, which is to be processed. By the term web material mentioned in this context, there is meant, in the graphics industry, material webs which are to be printed on one or more sides. These material webs, whether printed on one side or on both sides, may also include individual lengths of material web which are initially cut longitudinally, and then brought together again, in the angle-bar superstructure of a web-processing rotary printing machine.
In a further refinement of the concept upon which the invention is based, on that side of the former plate which is directed away from the web travel plane, the closure element, which is directed towards at least one of the slot-like openings, can be engaged with the former-plate side and withdrawn or disengaged therefrom. In an advantageous configuration, the closure element exceeds to a considerable extent the width of the former-plate openings assigned thereto. The configuration of the extent of overlap between the closure element and the material of the former plate extending alongside the slot-like opening makes it possible to increase further the restricting or throttling action which can be achieved as the closure element is engaged with the rear side of the former plate. Depending upon the extent by which the closure element is engaged with the rear side of the former plate, the gaseous-medium volume flowing out of the air cushion can be regulated extremely accurately.
With respect to the longitudinal extent of the closure element, at the top end thereof in the web travel direction, it is advantageously disposed so that it can be pivoted about a pin on the rear side of a first longitudinal folding device. In order to influence the air cushion, the closure element may advantageously extend over the entire length thereof, as viewed in the web travel direction, between the top crossmember of a first longitudinal folding device and a bottom crossmember. Assurance is thereby provided that influencing of the air cushion, i.e., the fluid-volume flows emerging from the air cushion, is provided by advancing or withdrawing the closure element, which extends in a web travel direction, it being possible for these movements to be performed by motor or manually. Depending upon the type of configuration and customer requirements, it is possible for the closure element, that can be actuated via spindle drives, for example, to be adjusted to the web-material width, respectively, which is to be processed, either via a handwheel or via an electric or pneumatic high-speed drive or the like, for example, even in the context of pre-setting when a new print job is being newly set up.
In another embodiment of the actuating device of the closure element, the latter may be actuated via spindle elements which can be moved at right angles to one another, it being possible for one of the spindle elements to be provided with a threaded section extending through an actuating lever whereon a cam is disposed for producing the advancement or withdrawal, i.e., the engagement and disengagement movement of the closure element. Depending upon the vertical displacement path covered by the actuating lever on the threaded section, it is possible to achieve a more-or-less pronounced extension movement of the cam, i.e. advancement of the closure element onto the rear side of the surface of the former plate. Depending upon the advancement, accordingly, the restricting cross sections formed between the rear side of the former-plate material and the front side of the closure element are of larger or smaller dimensions.
Due to the advantageous mounting of the closure element extending in the web travel direction, on the top crossmember of a first longitudinal folding device, it is possible, when the closure element is actuated, i.e. engaged with or advanced onto the rear side of the former-plate material, to achieve more pronounced engagement or advancement of the closure element, by way of the top region thereof, onto the first slot-like opening of the former plate, i.e., to achieve a greater restricting action in the wider region of the former plate. This may advantageously be achieved in that, when actuated, the closure element describes a rotary movement with respect to the pivot pin thereof.
It is advantageously possible for a vertical movement of the actuating lever, whereon the cam is accommodated, the vertical movement being achieved via a spindle of the spindle drive elements, to be converted into a movement wherein the cam is retracted or extended from the retracted position into an advanced position, respectively.
The device proposed in accordance with the invention for the contact-free guidance of web-like material over a surface may advantageously be used in web-processing rotary printing machines in the graphics industry. It is unimportant here whether the angle-bar superstructures of such web-processing rotary printing machines, whether for jobbing or for newspapers, process material webs which are printed on both sides or on one side or whether, in the angle-bar superstructures of such rotary printing machines, individual material webs are divided up into lengths of web which, after turning or rotation, are brought together again and then run into a folding module.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a device for contact-free guidance of a web material over a surface, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein: